USGS Water-Year Summary 2024
12115700 BOULDER CREEK NEAR CEDAR FALLS, WA
LOCATION - Lat 47°21'59", long 121°41'30" referenced to North American Datum of 1927, in NW 1/4 NW 1/4 sec.29, T.22 N., R.9 E., King County, WA, Hydrologic Unit 17110012, Snoqualmie National Forest, on left bank 5.8 mi southeast of Cedar Falls, and at mile 0.4.
DRAINAGE AREA - 4.64 mi².
REVISIONS HISTORY - Discharge for the period Aug. 19, 2019 to Aug. 21, 2019 was revised on Nov. 20, 2020 based on revision of zero flow discharges.
SURFACE-WATER RECORDS
PERIOD OF RECORD - March 1983 to current year.
GAGE - Water-stage recorder and crest-stage gage. Datum of gage is 1,610 ft above NGVD of 1929, from topographic map and is 1,662.24 ft above NAVD of 1988 (from USGS GNSS survey completed on July 15, 2022).
EXTREMES FOR PERIOD OF RECORD -
Maximum discharge, 1,800 ft³/s, Nov. 23, 1986, gage height, 4.16 ft, from rating extended above 524 ft³/s, but discharge may have been higher Jan. 7, 2009, discharge undetermined; maximum gage height, 6.20 ft, Feb 28, 2022; no flow for many days during July through October most years.